The present teachings relate to microfluidic devices, and methods for using such devices. More particularly, the present teachings relate to devices and methods that allow for the manipulation and processing of micro-sized amounts of fluids in a microfluidic device.
Microfluidic devices are useful for manipulating micro-sized fluid samples. There continues to exist a need for devices and methods for achieving quick, simple, reliable, and cost effective fluid manipulation control in microfluidic devices to efficiently process micro-sized fluid samples therein.
According to various embodiments, a microfluidic device is provided including a one-directional microball valve. The one-directional microball valve can be situated within a passageway of the microfluidic device and can control fluid flow between microfluidic features formed in or on the microfluidic device.
According to various embodiments, the microball valve can include at least one ball element that includes an outer-peripheral feature that mates with an inner-peripheral feature of a corresponding valve seat. The valve seat can be situated between an entrance opening and an exit opening of a passageway and can be defined by a portion of the passageway. Alternatively, a microball valve and seat assembly can be disposed in a through hole formed in a substrate.
According to various embodiments, the microfluidic device can include a substrate that includes a pathway formed therein. The pathway can include a passageway with an entrance opening and an exit opening separated by a one-dimensional microball valve. The passageway can be positioned between and in fluid communication with two adjacent but separated microfluidic features of the microfluidic device. The through passageway can taper outwardly between the entrance opening and the exit opening. The entrance opening can have a first minimum dimension and the exit opening can have a second minimum dimension that is greater than the first minimum dimension. The minimum dimensions can be diameters.
According to various embodiments during operation, the ball valve element can be unseated from the valve seat by the force of fluid flowing in a direction from the entrance opening of the passageway to the exit opening. The ball valve element can be forcibly seated against the valve seat by way of backpressure or reverse fluid flow caused by fluid disposed downstream of the ball element and flowing in a direction from the entrance opening toward the exit opening.
According to various embodiments, a method is provided for interrupting fluid communication through a microfluidic device by utilizing a one-directional microball valve. The method can include manipulating a fluid to unseat the microball and flow in a direction from the entrance opening toward the exit opening. The microball element can then be caused to seat against the valve seat to at least partially prevent or interrupt fluid flow in a direction from the exit opening toward the entrance opening. The method can include multiple seating and/or unseating operations of the microball with respect to the valve seat.